Re: [Gzz] PEG 1003

[Benja Fallenstein]

Tuomas Lukka wrote:

> > Note also that not all vobs need a box/shape. For text vobs, it 
> > suffices in principle to have a position, which can be given through a 
> > translation (IF somebody else takes care of the clipping).
> >    
>
> And scale. Don't forget the scale.

Yes, but there's the difficulty in AWT, where fonts scale non-uniformly 
(20pt isn't two times as high as 10pt). As we need to determine the cell 
box size through the font size, we cannot easily pass the scale through 
the vob system... Though I'd prefer it that way.

The question here is whether to let text vobs in GL determine their size 
through the scale passed by the vob system, or whether also to respect 
the font size passed to them in their constructor... probably the former.

The problem with having scale in OrthoCoorder is: Let's assume we have a 
coordsys showing a window, with cells in it. If we put the window 
coordsys into another coordsys scaled by factor 2, the rect bg vobs in 
the window would scale uniformly by factor 2, but the fonts would scale 
by something else, probably a little more. That would look very ugly, as 
the text would be badly clipped. :-(

> > The information EVERY vob (I think) needs to draw itself is:
> > - a position on the screen
> > - a shape for clipping
> >
> > The clipping shape can be set in the drawing context before the vob is 
> > asked to draw itself, so that the vob needn't worry about it.
> >    
>
> But what about the shape? How does the techreport stuff work here?

Sorry, I don't understand the question: What do you mean by, "what about 
the shape?"

> > In affine coordinate systems, for EVERY vob we also need:
> > - unit vectors of the affine transformation, for 
> > rotation/scaling/skewing
> >    
>
> Not only in affine: you do need the width-height for scaling the 
> text inside cells in the usual views.

As I explained above, this is made difficult by AWT's non-uniform font 
scaling... Currently for AWT, each text vob stores its scale as a field 
inside itself. The vob scene doesn't know anything about it.

- Benja